1. Technical Field
The invention relates to a compressor with one or more cylinders arranged horizontally and with a crankshaft in a crankcase.
2. Prior Art
U.S. Pat. No. 1,791,672 has disclosed a compressor for producing compressed air with two cylinders in a horizontally opposed arrangement. A common crankshaft mounted in a crankcase is driven by an electric motor. The electric motor and the cylinders lie in the same horizontal plane. On its underside, the electric motor is mounted on a foundation or bolted to the latter. The surface area required for the arrangement is relatively large.
It is the object of the present invention to provide a compressor of as compact construction as possible.
The compressor according to the invention is characterized in that the crankshaft is aligned vertically, in that a drive assembly coupled to the crankshaft is arranged underneath the at least one cylinder, in that a fan coupled to the drive assembly or to the crankshaft is provided, and in that the fan produces an air flow which is guided upwards along the drive assembly and along the at least one cylinder.
In contrast to the prior art described above, the drive assembly, preferably an electric motor, is arranged underneath the cylinders. This results in a significantly reduced surface-area requirement. In addition, the ventilation and cooling of both assemblies can be performed by a common flow of air.
The vertical arrangement according to the invention, with the cylinders and the drive assembly one above the other, preferably has two cylinders in a horizontally opposed arrangement. Embodiments with just one cylinder or with a plurality of cylinders in a different arrangement, for instance a star or V arrangement, are also possible, however. In all cases, the cylinders are provided transversely to the vertical crankshaft or drive shaft.
It is advantageous if the drive assembly is coupled to the crankshaft in the manner of a direct drive. However, an indirect drive via a gearbox is also possible.
A fan for producing a flow of air is arranged underneath the cylinders and, in particular, underneath the drive assembly. The fan is preferably designed as a radial fan, the air which flows in axially in a region of the fan away from the cylinders flowing out in the radial direction and brushing upwards laterally along the drive assembly and/or along the cylinders. An upward flow of air is produced for the cooling air and the intake air. The drive assembly and the cylinders are provided with cooling ribs. The upward-flowing air brushes past these and produces effective cooling. Thanks to the compact construction of modern electric motors, the cylinders project laterally and lie precisely in the flow of cooling air.
A (first) intake filter, preferably a filter mat, is provided in the region where the air enters the fan. This mat lies close to an inlet opening of an inlet housing arranged ahead of the fan.
The cylinders are assigned a (second) air filter, in particular an air filter common to a plurality of cylinders. The air filter is provided above the cylinders, in particular centrally. Air inlet openings of the air filter are situated in the region of the upward-flowing air mentioned above.
The air filter has an intake regulator, allowing output to all the cylinders connected to be interrupted quickly and thus allowing the operation of the compressor to be adapted to a lower compressed-air requirement.
By suitable guidance of the intake air (of the air to be compressed), it is possible to avoid feeding warm air into the air filter. It is advantageous if the intake air is guided from an intake opening underneath the cylinders to the air filter arranged above the cylinders. The intake-air guide is a tube of appropriate cross section. The intake opening is at a sufficient distance from heat-radiating surfaces, in particular cooling ribs. The actual distance will depend on the specific temperature and flow conditions.
It is advantageous if the upward flow of air is guided along the cylinders and along the crankcase and/or along the drive assembly by air guide members. This makes it possible to achieve more rapid heat dissipation.
The air guide members are decoupled from the cylinders in terms of vibration.
The compressor assemblyxe2x80x94the cylinders, the crankcase and the drive assemblyxe2x80x94is mounted in a housing. The air guide members are associated with the housing, while the compressor assembly is mounted in the housing in such a way that it can oscillate.
The air to be compressed is fed to the cylinders on their upper sides and removed from them as compressed air on the undersides. Corresponding compressed-air lines run in a plane underneath the cylinders and lie in the upward flow of air.
The cylinders are connected to one another by a common compressed-air line. This compressed-air line continues from one of the cylinders and is passed around the crankcase in the same horizontal plane, in particular through 180xc2x0 or more. At the same time, the encircling compressed-air line is at an adequate distance from the crankcase, thus ensuring that the heat of the lines is dissipated by rising air which is as cool as possible.
It is advantageous if the air filter arranged close to the cylinders has thermally insulated walls, in particular an insulating base plate. This avoids heating of the incoming air by the air-filter housing.
The drive assembly and the cylinders form a unit in terms of vibration. The resonant frequency is correspondingly low. This is additionally lowered by further measures. The unit is, for instance, mounted at a relatively low level. This purpose is served by supporting arms, the free ends of which are mounted on the housing at mounting points at a level below a transition between the cylinders and the drive assembly. At the end adjoining the unit, the supporting arms engage between the crankcase and the drive assembly, for instance. The free ends of the supporting arms rest on damping elements, These are arranged on the housing at the level of the centre of gravity of the unit capable of oscillation, on corresponding supporting beams or ties.
The supporting arms provide a star-shaped mounting for the unit in the housing. In this arrangement, the crankcase is at the centre of the mounting points.
Finally, the cylinders are assigned additional weights, advantageously radially to the outside of the cylinders with respect to the rotation of the crankshaft. The additional weights make it possible to increase the mass moment of inertia about the centre of gravity of the unit and thus, in particular, make it possible to counteract the formation of torsional vibrations.
Further features of the invention will become apparent from the claims. Overall, all the features disclosed are essential to the invention, both individually and in combination with others.
Advantageous embodiments of the invention will be explained in greater detail below with reference to drawings, in which;